Timeline, versions and checkpoints

Every change to a skin – yours and the agent's – becomes a step in the timeline at the bottom.

Undo, redo and replay#

• Undo / Redo step back and forward (⌘ Z / ⇧ ⌘ Z; Windows: Ctrl).
• Click a step to go to that point in history. Later steps are dimmed.
• Replay plays through the changes step by step.
• Hover a step to see what changed and who made it.

If you make a new edit after going back, the previous end is not lost: it is kept as an automatic checkpoint before the new path starts.

Versions & checkpoints#

History beside the timeline opens Versions & checkpoints:

• Inspect each change and its exact pixel differences.
• Open any earlier version.
• Revert one change – yours or the agent's – as a new step, while later, unrelated changes stay. If a later change painted over the same pixels, the revert is refused instead of overwriting it.
• Save a named checkpoint and restore it later as a new, undoable change.

How much is kept#

A skin keeps up to 100 changes and 8 checkpoints (7 named, 1 for automatic backups) within a 700 KB budget. Named checkpoints stay until you delete them; the oldest changes and automatic checkpoints expire when the budget is full. The first position in the timeline is therefore the oldest version still kept, not always the original import.

History, messages and marks are private: they are never part of a published skin or an exported PNG.

For agents#

Agents use read_history, read_history_change, compare_versions, checkout_history, undo, redo, revert_history_change and the checkpoint tools. Every change to history needs fresh revisions; see Guide for agents.